clark



. (No Model.)

2 sheets-sheet 1. l W. CLARK.

PHOTOGRAPHIG GAMBRA. I

Patented Apr. 26, 1887.

/I: ATTORNEY (No Model.) 2 Sheets-Sheet 2.

W. CLARK.

PHOTOGRAPHIG CAMERA.

No. 361,672. Patented AprfZ, 1887..

Wl T NESSES IN VEN T 0R UNITED STATES PATENT OFFICE.

VALTER CLARK, OF NEV YORK, N. Y.

PHOTOGRAPHIC CAMERA.

SPECIFICATION forming part of Letters Patent No. 361,672', dated April 26, 1887.

T all whom, it may concern,.-

Be it known that I, VALTER CLARK, acitizen of the United States, residing at New York,

' in the county and State of New York, have invsurface of the sensitive plate.

vented certain new and useful Improvements in Photographic Cameras, of which the following is a full and complete specification, reference being had to the accompanying drawings, forming a portion thereof.

The object of my invention is to improve and render more certain the action of the devices which produce the instantaneous effect in photographic cameras, and also to improve the devices for focusing.

My invention consists of a camera-box, preferably of the kind having the lens and its tubes within the boX provided with a hinged lid which, when lifted, carries with it a groundglass focusing-plate, which is maintained in a horizontal position by a certain arrangement of links, and is always at the same distance from the mirror upon which the incident rays are received that the said mirror is from the The groundalso provided with a hood so arglass plate is fold within the box when the lid ranged as to is lowered.

My invention further consists in placing within the camera box a drum revolving upon a vertical axis under the action of an adj ustable coiled spring, controlled by a lfrictionwheel, open for a portionof its cylindrical sur face and provided in the closed portion with a window, for the admission of the light-rays when the window passes the aperture of the lens.

My invention further consists of certain details of construction of the various parts to render their action more certain and efficient and to insure the entire exclusion of light from the dark chamber.

These minor features will be' more fully hereinafter set forth.

In the drawings, Figure l is a vertical section of the camera on the line z c of Fig. 2.'

The lid is shown raised, a portion of the outer end of the lid being omitted. Fig. 2 is a hori- Zontal section of the camera on the line m :c of Fig. 1. Fig. 3 is a cross-section ofthe camera on the line y y of Fig. 2, showing in vertical projection the entire lid raised and the hood Application filed October 26, 1886. Serial No. 217,220. (No model.)

in working position. Fig. 4 is a plan view of the frictional device for controlling the motion of the revolving drum.

A is the camera-box, provided with the opening a, the partition A', plate-holder guides A, slats A, and cheek-pieces A4.

B is the lens-tube operated by the pinion b and thumb-piece b2.

C is the plate-holder; c, a sensitive plate; c3, the front and back opaque slides; 0*, springs to keep the holder in place.

D is the internal lid hinged to the front of the boX at d, and having the opening d2, for light to pass from the mirror Eto the groundglass focusing-plate F. This lid D when down is held in place by certain projections on the plate-holder resting upon it. By removing the plate-holder the lid D can be turned upon its hinged end and raised for the removal of the drum H, which is pivoted to the lid D and to a support, G.

I is a clock-spring to rotate drum; K, afriction-wheel to control the rotation of the drum; h, a window in the drum; m m2, links to support the lid L; m3, a link, and m4 a bar or support attached to the camera-box to support the outer end of the ground-glass plate F. These links are so contrived as to keep the plate always in a horizontal position when the lid L is raised.

N is an india-rubber hood mounted upon the folding wire frame n.

O is a buffer to stop the rotation of the drum -H at the proper point; P, a catch to hold or release the drum, operated from the outside of the camera by the long rod R, passing through the support i.

The arrows indicate the direction of motion of the various parts.

Taking up the drum H in detail, it consists of a circular top having an opening in the IOO lthe rod R. To counter-balance the weight of the mirror a small weight, S, is added to the top of the drum.

The pivot It at the top of the drum passes up through the lid D and has fixed upon it a smooth-rimmed wheel, K, against which a spring, k, Fig. 4, presses with more or less pressure, according to the position ofthe cam K4, which is pivoted at kf" to the lid D, and presses against the latch 7a2, sliding in k3.

The mirror, inelosed in a boX open at the top, is secured in the drum atan angle of fortyi five degrees opposite the opening for focusing,

by means of the upper and lower supports,c e. VvThen the Window h is opposite the lens it (the mirror) has turned away entirely out of the way ofthe beam of light. The iianges h, iitting into grooves in slide D, eifectually prevent any leakage of light into the camera at the top.

The operation is as follows: The camera havingbeen placed in position and directed at the objecttobephotographed,thelenses arethrown out, the cap removed, and the lid L raised until i it is supported by the links mm2. Thegroundglass F is automatically brought into positlon and the hood distended. The drum is brought into such position that the reflecting-surface of the mirror is opposite the lens. Uponlooking at the ground-glass plate the image of the object will be seen there exactly as it would be thrown upon the sensitive plate were the drum in proper position. XVhen the lens has been adjusted so that the object is clearly defined upon the ground glass, the catch P is withdrawn by means of the lever or rod R, and the drum revolving in the direction 'of the arrow brings the window 7i opposite the lens,and continues to revolve until itis brought to a stop by the buffer O, atixed to the side of the camera. During the instant that the window h is passing by the lens the beam oi'light transmitted from the object is free to pass to the sensitive plate and act upon it, and is then immediately cut off by the further revolution ofthe drum, bringing the inelosed cylindrical surface between the lens and sensitive plate.

Should more force be required to rotate the drum, this can be obtained by winding up the cloclespring I by means of the springarmt` and pin i?. This spring is retained at any required tension by the hol'es or notches i, into which the pin i2 slips and is retained by the spring-arm z'. To preventthedrum rotatingtoo rapidly the spring K can be brought to bear more iirmly against the wheel K by the cam k. I clairn- 1. A photographie camera provided with an inner lid, D, to which is pivoted a revolving drum containing the focusing-mirror, said inner lid being retained in place by a projection on the plate-holder, substantially as described, and for the purposes specified.

2. A photographie camera provided with a revolving drum mounted on a vertical axis and placed immediately behind the lens, said drum carrying the focusing-mirror, and provided with a window to admit the passage of light at the proper time through the lens to the sensitive plate, as herein described and shown.

3. In a photographie camera, the hinged lid L and ground-glass plate F, pivoted thereto and raised and supported by the links m m2 on m, the parts being so arranged and adjusted that when raised the plate F'is always at the vsame distance from the focusing-mirror that the sensitive plate is from said mirror, as herein described and shown.

In testimony whereof I have hereunto set my hand.

VALTER CLARK. Vitnesses:

GEO. H. SoNNEBoRN, W. E. S'rEARNs. 

